McMaster-Carr logo
    Filter by
    System of Measurement
    Width
    Attribute Image
    Cross Section Shape
    Material
    Industrial Info Compare
    Fractional Width
    Hardness Rating
    Industrial Info Compare
    Fractional OD
    Fractional ID
    DFARS Specialty Metals
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    Industrial Info Compare
    Specifications Met
    Industrial Info Compare
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    13 Products
    About O-Rings
    industrial info icon

    Find the right size, compare compatible materials, and choose the best cross section shape for your O-ring.

    Oil-Resistant Buna-N O-Rings

    Made of Buna-N, these O-rings resist grease, hydraulic oil, and motor oil—plus mild chemicals and water. However, Buna-N is not for use with brake fluid. These O-rings are commonly used to create multidirectional seals between two parts in power transmission assemblies, hydraulic cylinders, and pneumatic cylinders. They resist compression and tearing to keep their shape over time. All have shelf life, a cure date, and a traceable lot number printed on the package.
    Inch
    Image of Product. Front orientation. O-Rings. Oil-Resistant Buna-N O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Oil-Resistant Buna-N O-Rings.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-30 to 212Black509452K4000000000000000
     

    High-Temperature Soft Silicone O-Rings

    Easier to compress than standard silicone O-rings, these O-rings create a better seal in enclosures, reservoirs, and other low-pressure equipment. They can withstand temperatures up to 400° F. All have shelf life, a cure date, and a traceable lot number printed on the bag.
    Inch
    Image of Product. Front orientation. O-Rings. High-Temperature Soft Silicone O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. High-Temperature Soft Silicone O-Rings.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 50A (Soft)ASTM D2000, SAE AS568-85 to 400Red51173N5360000000000
     

    High-Temperature Parker S1138 Silicone O-Rings

    Image of Product. Bottom orientation. O-Rings. High-Temperature Parker S1138 Silicone O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. High-Temperature Parker S1138 Silicone O-Rings.
    Use these O-rings in temperatures up to 400° F. Made of Parker S1138 silicone, they’re pure enough for food or pharmaceutical applications—they’re USP VI certified. These O-rings are also FDA compliant for direct contact with food. All come with a cure date and a traceable lot number printed on the bag.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Food Industry Std.
    USP
    Class
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200FDA Compliant 21 CFR 177.2600
    		VI-60 to 400Red109396K288000000000000000
     

    Oil-Resistant Hard Buna-N O-Rings

    Harder than standard Buna-N O-rings, these 90A durometer O-rings are more durable and wear resistant. They resist petroleum and grease, so they’re often used in hydraulic and pneumatic systems. All have shelf life, cure date, and a traceable lot number printed on the bag.
    Inch
    Image of Product. Front orientation. O-Rings. Oil-Resistant Hard Buna-N O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Oil-Resistant Hard Buna-N O-Rings.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    3/16 Fractional Width (0.210" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 90A (Hard)ASTM D2000, SAE AS568, SAE J200-30 to 250Black505308T34800000000000
     

    Low-Temperature Chemical-Resistant FEP-Encapsulated Silicone O-Rings

    Image of Product. Bottom orientation. O-Rings. Low-Temperature Chemical-Resistant FEP-Encapsulated Silicone O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Low-Temperature Chemical-Resistant FEP-Encapsulated Silicone O-Rings.
    Seal lines and valves in HVAC systems, freezers, and other cold applications exposed to chemicals. Made with an FEP casing, these O-rings are protected against chemicals such as methanol and boric acid. They’re a step up from Viton® fluoroelastomer in chemical resistance but less robust than PTFE. Their silicone core stays compressible even in temperatures as low as -75° F. All have a shelf life, cure date, and traceable lot number printed on the bag.
    Fractional
    Each
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Core Hardness
    Specs. Met
    Food Industry Std.
    Temp. Range,
    ° F
    Color
    1-9
    10-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 55D (Hard)Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200FDA Compliant 21 CFR 177.1550, FDA Compliant 21 CFR 177.2600
    		-75 to 400Clear with Red Core9319K643000000000000
     

    Ultra-Chemical-Resistant FEP-Encapsulated Viton® Fluoroelastomer O-Rings

    Image of Product. Front orientation. O-Rings. Ultra-Chemical-Resistant FEP-Encapsulated Viton® Fluoroelastomer O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Ultra-Chemical-Resistant FEP-Encapsulated Viton® Fluoroelastomer O-Rings.
    An FEP casing protects these O-rings from moisture and harsh solvents such as acetone, methanol, and boric acid. If the casing wears away, the Viton® fluoroelastomer core will continue to ward off chemicals. These O-rings are more flexible than PTFE O-rings and resist chemicals better than standard Viton® O-rings. They’re often used as seals in centrifugal pumps and gas venting valves. All come with shelf life, a cure date, and a traceable lot number on the bag.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Fractional
    Each
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Core Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    1-9
    10-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 55D (Hard)Durometer 75A (Medium)ASTM D2000, ASTM D2116, SAE AS568, SAE J200-15 to 400Clear with Black Core93445K581000000000000
     

    Chemical-Resistant Viton® Fluoroelastomer O-Rings

    Made of Viton® fluoroelastomer, these O-rings combine the oil resistance of Buna-N with the heat tolerance of silicone. They also resist a variety of chemicals, including benzene, butyl alcohol, and ethylene glycol. They’re often used to seal hydraulic systems and equipment in crude oil refineries. All have shelf life, a cure date, and a traceable lot number printed on the bag.
    Inch
    Image of Product. Front orientation. O-Rings. Chemical-Resistant Viton® Fluoroelastomer O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Chemical-Resistant Viton® Fluoroelastomer O-Rings.
    Brown—Brown O-rings help you tell Viton® fluoroelastomer apart from other materials.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Choose a
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 75A (Medium)ASTM D2000, SAE AS568, SAE J2000 to 400Black, Brown109464K44700000000000000000
     

    Water- and Steam-Resistant Parker E0603 EPDM O-Rings

    Image of Product. Front orientation. O-Rings. Water- and Steam-Resistant Parker E0603 EPDM O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Water- and Steam-Resistant Parker E0603 EPDM O-Rings.
    Trusted for their quality and consistency, these E0603 EPDM O-rings resist water, steam, and glycol-based fluids, including brake fluid. They’re often used to seal plumbing and refrigeration systems, since they won’t swell or break down in moist environments. All have a cure date and traceable lot number printed on the bag.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-70 to 250Black609557K294000000000000000000
     

    High-Temperature Silicone O-Rings

    Made of silicone, these O-rings can withstand temperatures up to 400° F or higher. They're FDA compliant for direct contact with food, so they're often used on hot food lines. They're also used to seal HVAC systems. All come with a cure date and a traceable lot number printed on the bag.
    Inch
    Image of Product. Bottom orientation. O-Rings. High-Temperature Silicone O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. High-Temperature Silicone O-Rings.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Food Industry Std.
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200FDA Compliant 21 CFR 177.2600
    		-65 to 400Red109186N336000000000000000
     

    Oil- and Abrasion-Resistant Polyurethane O-Rings

    Image of Product. Front orientation. O-Rings. Oil- and Abrasion-Resistant Polyurethane O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Oil- and Abrasion-Resistant Polyurethane O-Rings.
    More abrasion resistant than Buna-N O-rings, these polyurethane O-rings resist mineral oil, motor oil, and ethylene glycol. They have a round profile and are suitable for a wide range of static and dynamic sealing applications. All are sized to the SAE standard AS568.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-40 to 200Black19558K3350000000000
     

    Water- and Steam-Resistant EPDM O-Rings

    Made of EPDM, these O-rings have excellent resistance to water, steam, and glycol-based fluids, including brake fluid. They’re often used to seal plumbing and refrigeration systems, since they won’t swell or break down in moist environments. All have shelf life, a cure date, and a traceable lot number printed on the bag.
    Inch
    Image of Product. Front orientation. O-Rings. Water- and Steam-Resistant EPDM O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Water- and Steam-Resistant EPDM O-Rings.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-65 to 300Black608785N2190000000000000000
     

    Oil-Resistant Mil. Spec. Buna-N O-Rings

    Image of Product. Front orientation. O-Rings. Oil-Resistant Mil. Spec. Buna-N O-Rings.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Oil-Resistant Mil. Spec. Buna-N O-Rings.
    Choose these O-rings for their adherence to strict military standards for material and construction. Made of Buna-N, they stand up to a variety of oils and fuels as well as ammonia, ethylene glycol, and isopropyl alcohol. They’re also resilient and tear resistant. These O-rings are made in the U.S.
    MIL-I-45208—O-rings that meet MIL-I-45208 have undergone rigorous inspection for quality control.
    MIL-P-5315—O-rings that meet MIL-P-5315 are the best choice for use with hydrocarbon fuels. They’re often used in engine fuel systems in airplanes and other vehicles.
    Fractional
    Pkg.
    Dash
    No.
    ID
    OD
    ID
    OD
    Hardness
    Specs. Met
    Mil. Spec.
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    3/16 Fractional Width (0.21" Wide)
    317
    		15/161 5/160.912"1.332"Durometer 65A (Medium)ASTM D2000, SAE AS568, SAE AS3578, SAE J200MIL-I-45208-20 to 250Black105018T608000000000000
    317
    		15/161 5/160.912"1.332"Durometer 65A (Medium)ASTM D2000, SAE AS568, SAE J200MIL-P-5315-65 to 155Black254464T340000000000
     
    back to top